The treatment of food waste is an important challenge for certain industrial concerns and certain commercial firms such as large shopping centers.
Statutes now require that waste produced by them be taxed based on weight. The current tendency is therefore to reduce the weight of the waste produced.
Several methods are possible, comprising methods for drying the waste.
Document WO 2009/139514 teaches a system for drying food waste. The food waste is stored in a first container heated by an oil bath to 80° C. and comprising a device for stirring the waste and for supplying hot air. The steam created by heating the food waste in the container mixes with hot air. These gaseous effluents are discharged with a pipe. Then they pass into a filter to reach an indirect-contact condenser. The condenser comprises a plurality of cooling pipes and a plurality of fans. The effluents are then condensed in the condenser in order to store the condensate obtained in an additional container. The incondensable effluents are pumped by a pump to be deodorized, then mixed with outside air and heated to be reintroduced into the first container. The system described in this document uses many devices such as filters, deodorizers, catalysts, etc. These devices require much upkeep with considerable maintenance. In addition, the system as a whole consumes a large quantity of energy compared to the quantity of waste treated.
Document WO 2005/099920 teaches a system for treating food waste. This device also comprises a plurality of devices such as filters, a condenser, a heat exchanger, a radiator, a catalyst, a deodorizer, an ozone generator, etc. Moreover, the operating temperatures of the system can rise to 800° C. in certain parts of the system. The high temperatures as well as the operation of the many devices used require considerable consumption of energy and considerable maintenance.
Document EP 1 821 054 also teaches a system for treating food waste. The food waste is stored in a container comprising stirring means. The gaseous effluent is aspirated into an air-circulating fan. A portion of the waste is re-introduced into the container after passing through heating means. The other portion of the effluent is aspirated by a an exhaust fan after having been deodorized by a deodorizer and a heating means that heats the effluent up to a temperature of 350° C. In the same manner as in the foregoing documents, the system of this document requires considerable consumption of energy even if the number of devices is smaller. In addition, the recirculation of effluent into the container makes the system ineffective.
Document JP 2008-284483 teaches a device for drying waste. This device comprises a container for treating waste, a heating device, a vacuum pump. A device for cooling the gases generated in the container and a cyclone separator to discharge the gasified components such as water and fats are positioned between the container and the vacuum pump. This device requires several systems such as a cyclone separator and a cooling device which require considerable maintenance.